JP3020995B2 - Filler for resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is useful as a filler for resin, in particular, a sealing material for electronic components such as capacitors, connectors, resistors, and semiconductors, an insulating paste, and a heat dissipation sheet. The present invention relates to a simple resin filler.

[Conventional technology]

Resin encapsulants consisting of fillers such as fused silica and raw silica and epoxy resin or polyphenylene resin have significantly improved reliability and excellent moldability and mass productivity, so about 90% of the encapsulant is resin-encapsulated. Used as a stopping material.

However, in recent years, in the electric and electronic equipment industry, high integration of electric and electronic parts has been required in order to promote miniaturization and weight reduction, and encapsulants for electric and electronic parts,
Insulating pastes, heat dissipation sheets, and the like have been required to further improve heat dissipation. Accordingly, nitride powders such as silicon nitride and aluminum nitride have been proposed as fillers having better heat dissipation properties than fused silica or raw silica (Japanese Patent Application Laid-Open Nos. 60-4522 and 61-101522). , 62-43415
No.).

Although the resin composition using these nitride powders as a filler has certainly improved heat dissipation, the transfer molding and the injection molding are more effective than the conventional fused silica and raw silica as fillers. As a result, the spiral flow is remarkably reduced, which causes abrasion of the mold and high filling cannot be attained. Therefore, there is a disadvantage that the heat radiation properties of these nitride powders cannot be sufficiently utilized.

[Problems to be solved by the invention]

The present inventors have studied in detail the effect of the particle size of the nitride powder and / or the oxynitride powder on the flow characteristics in order to improve the above-described drawbacks. As a result, the nitride powder having a specific particle size distribution and The present invention has been completed by finding that the flow characteristics are specifically improved when oxynitride powder is used as the filler.

[Means for solving the problem]

That is, the present invention is a resin filler characterized by comprising an inorganic powder containing a nitride powder and / or an oxynitride powder having the following particle size characteristics.

(Particle size distribution) -1μ 5-10% -2μ 6-12% -3μ 10-16% -8μ 35-47% -24μ 51-63% -48μ 67-75% -96μ 88-92% 9 to 22 μm (RRS-n value) ≦ 0.80 Hereinafter, the present invention will be described in more detail.

Examples of the nitride and oxynitride in the present invention include nitrides such as silicon nitride and aluminum nitride, and oxynitrides such as silicon oxynitride, aluminum oxynitride, and sialon. When it is desired to impart higher thermal conductivity to the resin composition, aluminum nitride,
If silicon nitride or sialon is to be given more thermal shock resistance, silicon oxynitride or aluminum oxynitride is selected. Note that silicon nitride and sialon have two types of crystal forms, α-type and β-type, either of which may be used, or a mixture of both.
In the case of silicon oxynitride or aluminum oxynitride oxynitride, not only a crystalline substance but also an amorphous substance may coexist.

The nitride powder and oxynitride powder according to the present invention can be obtained by (1) a method of directly nitriding a metal such as metallic silicon, metallic aluminum or a silicon-aluminum alloy, and (2) a metal oxide such as silica, alumina, kaolin or mullite. (3) the above-mentioned metal and oxynitride, nitride and / or
(4) a method of (reducing) nitriding a metal oxide and a nitride, (5) a metal halide such as silicon chloride and aluminum chloride, and / or methyl silicate. And a method of producing directly from an organometallic compound such as triethoxy aluminum and ammonia and ammonia via a metal imide or a metal amide.

Of the above production, it is easy to adjust the particle size and specific surface area,
The methods (1) and (3) are preferable in that the heat dissipation, thermal shock resistance, and moldability of the resin composition can be further improved. On the other hand, (5) in that a filler having a reduced α ray can be easily obtained. Is preferred. When obtaining nitrides and / or oxynitrides by the above methods (1) to (5), if necessary, carbon, Ca, Mg, Mn, Y and lanthanide metal oxides, carbonates and oxalic acids At least one selected from salts and the like may be blended.

The purity of the nitride powder and / or oxynitride powder as the filler of the present invention is 70% or more, preferably 80% or more, and particularly preferably 90% or more. If the purity is less than 90%, at least one of the resulting resin composition has impaired electrical insulation, thermal conductivity, and thermal shock resistance.

When the filler of the present invention is obtained by the above-mentioned method (1) or (3), in order to ensure good electrical insulation and thermal shock resistance, the residual ratio of the unreacted metal is 1% or less, preferably 0%. .
It is important to determine the nitriding conditions so as to be 5% or less, particularly preferably 0.3% or less.

The purity of the filler of the present invention is represented by the ratio of the peak of the filler of the present invention to the sum of the heights of the peaks at predetermined positions of various impurity crystalline powders obtained from the X-ray diffraction chart and the filler of the present invention. Shall be allowed. In the case of silicon oxynitride or aluminum oxynitride, not only crystallized substances but also amorphous ones may exist, but broad peaks due to the amorphous ones should be excluded from the calculation when calculating the purity. I do.

In the present invention, the residual ratio of the unreacted metal is defined as the peak of the metal powder of the unreacted metal with respect to the sum of the heights of the peaks at predetermined positions of the metal powder and the nitride powder and / or the oxynitride powder obtained from the X-ray diffraction chart. It is assumed to be represented by the ratio of
Specific peaks are as follows.

Filler of the present invention (210) face of α-sialon Filler of the present invention (101) face of β-sialon Filler of the present invention (110) face of silicon oxynitride Filler of the present invention Aluminum oxynitride (440) face Filler of the present invention (210) face of α-silicon nitride Filler of the present invention (101) face of β-silicon nitride Filler of the present invention (101) face of aluminum nitride Impurity (101) of cristobalite Plane (101) plane of impurity α-quartz (113) plane of impurity α-alumina (120) plane of impurity mullite (111) plane of metallic silicon impurity (111) plane of metallic aluminum impurity (111) of β-SiC impurity Surface As the ionic impurities contained in the filler of the present invention,
Fe ⁺⁺ 5000 ppm or less, Na ⁺ 100 ppm or less, Cl ^- 50 ppm or less, preferably Fe ⁺⁺ 1000 ppm or less, Na ⁺ 30 ppm or less, Cl ^- 20
ppm or less, particularly preferably Fe ⁺⁺ 100 ppm or less, Na ⁺ 10 ppm or less, and Cl ^- 10 ppm or less. Especially when Na ⁺ exceeds 100 ppm or C
l ^- is moisture-proof reliability is inferior or exceed 50ppm.

The filler of the present invention needs to have a particle size distribution, an average particle size, and an RRS-n value shown in Table 1, and is preferably as shown in the table.

When the particle size distribution and the average particle size are beyond the range of the present invention in Table 1, the fine particle content is too large, the content of the fine particles is too large, the resin viscosity increases, and as a result, the flow is reduced or the kneading is insufficient. Burrs cannot be suppressed. On the other hand, the particle size distribution and the average particle size become coarse powder particle sizes beyond the range of the present invention in Table 1, and even if the particle size distribution and the average particle size are
Even within the range of the present invention, when the RRS-n value exceeds 0.80, the dilatancy is increased and the flow is reduced.

Although the particle size of the filler of the present invention is measured by a laser diffraction method, the particle size is measured by another measurement principle, for example, by a light transmission type natural sedimentation / centrifugal sedimentation, an electron microscope, a gascade impactor method, a Coulter counter method, or the like. It goes without saying that there is no problem in using the particle size measurement as long as the correction with the laser diffraction method is performed. It should be noted that currently commercially available laser diffraction particle size analyzers cannot detect particles of 0.1 μm or less due to the wavelength used. Therefore,
The content of the particles of 0.1 μm or less contained in the filler of the present invention may be any amount.However, if the content of the particles of 0.1 μm or less is large, defects such as very bulky workability and easy generation of dust may occur. If this is a problem, the content of particles of 0.1 μm or less may be limited.

The RRS-n value is a Rosin-Rammler represented by a straight line connecting one point of 10 to 30% by weight and one point of 70 to 90% by weight of the cumulative weight% from the maximum particle size in the RRS particle size diagram. Means the value of n. In the actual particle size measurement, if two or more straight lines connecting one point in the range of 10 to 30% by weight of the cumulative weight% from the maximum particle size and one point in the range of 70 to 90% by weight can be drawn. , A straight line with the smallest gradient.

Here, the RRS particle size diagram is a particle size diagram representing a particle size distribution according to the following Rosin-Rammler equation.

R (Dp) = 100exp (-b Dp n) ( where cumulative weight percent of wherein R (Dp) from maximum particle size to the particle size Dp, Dp is the particle diameter, b and n are constants) invention The particle size of the filler can be adjusted only by controlling the pulverization conditions.However, if necessary, dry classification such as gravity sedimentation such as wind sieves and cyclones, centrifugal type, inertia type, water sieve, sedimentation Fine powder can also be removed by classification, wet classification using a hydrocyclone, a decanter or the like, sieving, or the like.

10 times by weight or less, preferably 3 times by weight or less, particularly preferably 1 time by weight or less (including 0) with respect to the total weight of the nitride powder and / or oxynitride powder of the present invention, the shape of which is pulverized; Spherical, whisker-like, fibrous or flaky fused silica, raw silica, silica titania glass, cristobalite silica, aluminum silicate, alumina, titanium nitride, boron nitride and the like may be used in combination. If it exceeds 10 times the weight, at least one of the properties of heat dissipation, thermal shock resistance and humidity resistance is impaired. When using a filler other than nitride powder and / or oxynitride powder,
It is important to use different fillers according to the required properties of the sealing material. In other words, when importance is placed on thermal shock resistance and moisture resistance reliability, fused silica or silica titania glass is selected, and when importance is placed on thermal conductivity, titanium nitride, boron nitride, or alumina is selected. Raw silica, cristobalite silica, aluminum silicate, etc. are selected for thermal conductivity and cost reduction.

As the maximum particle size of the filler of the present invention, the smaller the particle size, the less the wiring, passivation film, bonding wire, etc. on the element surface are damaged or damaged during molding, but the gate clogging during transfer molding is reduced. The maximum particle size considered is 500 μm or less, preferably 149 μm.
It is particularly preferably 74 μm or less.

The content of the filler of the present invention in the resin composition is 20 to 97% by weight, preferably 30 to 95% by weight, and particularly preferably 40 to 90% by weight. When the content of the filler is less than 20% by weight, the moldability of the resin composition is excellent, but the thermal stress is large, and the heat shock resistance and the moisture resistance reliability are reduced. On the other hand, if the content exceeds 97% by weight, the moldability of the resin composition is impaired, unfilled portions and voids occur frequently, and the electric insulation and reliability are impaired.

As the resin in which the filler of the present invention is used, bisphenol epoxy resin, phenol novolak epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin,
Glycidyl ester type epoxy resin, glycidylamine type epoxy resin, epoxy resin such as halogenated epoxy resin, polybenzimidazole, polybenzoxazole, polybenzthiazole, polyoxadiazole,
Polypyrazole, polyquinoxaline, polyquinazolinedione, polybenzoxazinone, polyindolone, polyquinazolone, polyindoxyl, silicone resin, silicone-epoxy resin, phenolic resin, melamine resin, urea resin, unsaturated polyester, polyaminobismaleimide, diallyl phthalate Resin, fluorine resin, TPX resin (methylpentene polymer "trade name of Mitsui Petrochemical Company"), polyimide, polyamideimide, polyetherimide, 66-nylon, MXD-nylon, polyamide such as amorphous nylon, polybutylene terephthalate and polyethylene Polyester such as terephthalate,
Polyphenylene sulfide, modified polyphenylene ether, polyarylate, wholly aromatic polyester, polysulfone, liquid crystal polymer, polyetheretherketone, polyethersulfone, polycarbonate, maleimide-modified resin, ABS resin, AAS (acrylonitrile, acrylic rubber, styrene) resin, AES (Acrylonitrile-ethylene-propylene-diene rubber-styrene) resin and the like, and the sealing material, the electric insulating paste and the like are usually epoxy resin, silicon-epoxy resin, and the adhesive strength to metal at higher temperature. For maintaining bending strength, etc., polyaminobismaleimide-based resins such as Kelimide (trade name of Mitsui Petrochemical Co., Ltd.) and BT resin (trade name of Mitsubishi Gas Chemical Co., Ltd.), sealing for reusing gates and runners Polyphenylenesul resin I de, polyphenylene sulfide and liquid crystal polymers and / or epoxy group-containing polymer and alloy, etc. are preferable.

The resin composition using the filler of the present invention contains rubber components such as butyl rubber, acrylic rubber, ethylene propylene rubber, silicone rubber, polyester elastomer, and polybutadiene in these resins in order to enhance thermal shock resistance. Can also. Further, if necessary, benzoguanamine, 2,4-dihydrazino-6-methylamino-S-triazine, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-
Imidazole derivatives such as ethyl-4-methylimidazole, various amine complexes of boron fluoride, trisdimethylaminomethylphenol, 1,8-diazabicyclo (5,4,0)
Tertiary amine compounds such as undecene-7 and benzyldimethylamine, dicyandiamide, amino alcohol compounds obtained by reaction of bisphenol type epoxy resin or cresol novolak type epoxy resin with ammonia, and nitrogen-containing curing such as adipic hydrazide (promoted) )
Phenolic hardeners such as phenol novolak and cresol novolak, acid anhydride hardeners such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride, triphenylphosphine, tricyclohexylphosphine, methyldiphenyl Organic phosphine-based curing (acceleration) agents such as phosphine, tolytriosphin, 1,2-bis (diphenylphosphino) ethane, bis (diphenylphosphino) methane, bis- (tributyltin) oxide, tin dioctenoate, octane Curing catalysts such as antimony acid, tin butyrate, lead monoxide, lead sulfide, and lead carbonate; polymerization catalysts such as platinum compounds; vulcanizing agents such as benzoyl peroxide and dicumyl peroxide; carnauba wax, montana wax, polyester oligomer, and silicone oil , Low molecular weight Ethylene, paraffin, metal salts of linear fatty acids, acid amides, lubricants, mold release agents, such as esters, 2,
6-di-t-butyl-4-methylphenol, 1,3,5-tris (2-methyl-4-hydroxy-5-t-butylphenol) butane, distearylthiodipropionate, trinonylphenyl phosphite, Stabilizers such as tridecyl phosphite, 2,2'-dihydroxy-4-methoxybenzophenone, 2 (2'-hydroxy-5-methylphenyl) benzotriazole, 4-t-butylphenyl salicylate, ethyl-2- Light stabilizers such as cyano-3,3-diphenyl acrylate, colorants such as red iron oxide and carbon black, antimony trioxide, antimony tetroxide, triphenylstibine, hydrated alumina, ferrocene, phosphazene, hexabromobenzene, and tetrabromophthalate Acid anhydride, tricresyl phosphate, tetrabromobisphenol A, odor Flame retardants such as fluorinated epoxy derivatives, vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, β- Silane coupling agents such as (3,4-epoxycyclohexyl) ethyltrimethoxysilane, isopropyltriinstearoyl titanate, dicumylphenyloxyacetate titanate, bis (dioctylpyrophosphate) oxyacetate titanate, isopropyltridecylbenzenesulfonyl titanate, etc. And an aluminum-based coupling agent such as acetoalkoxyaluminum diisopropylate.

The resin composition containing the filler of the present invention is prepared by sufficiently mixing a predetermined amount of each of the above-mentioned components with a Henschel mixer or the like, and then using a roll, a Banbury mixer, a kneader, a grinder, an azihomo mixer, a twin screw extruder, It can be manufactured by heating and kneading by a known kneading means such as a screw extruder.

〔Example〕

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” mean “parts by weight” and “% by weight”.

Production of β-silicon nitride powder 100 parts of metal Si powder (maximum particle diameter 149 μm, average particle diameter 10 μm, purity 99.9%), lamp black 70 parts, Aerosil OX
-50 (manufactured by Nippon Aerosil Co., Ltd.), 30 parts of a 5% aqueous solution of ammonium salt of carboxymethylcellulose were mixed in a V-blender for 20 minutes, then pressed in a mold, dried, degreased, and heated at 250 ° C./hr in a nitrogen stream. Temperature to 1450 ° C,
The reaction was further carried out at 50 ° C. for 48 hours to obtain a reaction mass. This reaction mass is coarsely crushed and then pulverized for 2 hours with a ball mill, and the aperture is 149 μm.
The coarse particles were removed and classified with a sieve mesh of
3 was obtained. As a result of X-ray diffraction of these powders, metallic Si 0.08
%, Silicon oxynitride 0.6%, α-silicon nitride 1
4.3%, the balance was β-silicon nitride.

The powders A-1 to A-3 were further classified by using a turbo classifier (manufactured by Nisshin Engineering Co., Ltd.) air classifier while changing the classification points to obtain powders A-4 to A-12.

Manufacture of α-silicon nitride powder 100 parts of metal Si powder (maximum particle size 149 μm, average particle size 10 μm, purity 99.9%) and 10 parts of 5% aqueous solution of ammonium salt of carboxymethylcellulose are mixed in a V blender for 20 minutes, and then a mold is prepared. Press molding, drying, degreasing, then 1000 in a nitrogen stream
Temperature up to 200 ℃ / hr, 10 ℃ / hr between 1000 and 1450 ℃
And the reaction was further allowed to proceed at 1450 ° C. for 10 hours to obtain a reaction mass. After pulverizing the reaction mass, the mixture was finely pulverized for 6 hours and 2 hours with a ball mill, and coarse particles were removed with a sieve mesh having an opening of 141 μm to obtain powders A-13 and A-14 shown in Table-2. As a result of X-ray diffraction, metal
Si was 0.04%, α-silicon nitride was 91.2%, and the balance was β-silicon nitride.

The powder A-13 was further classified with a turbo classifier (manufactured by Nisshin Engineering Co., Ltd.) air classifier while changing the classification point to obtain powder A-15.

Manufacture of crushed aluminum nitride powder 100 parts of atomized aluminum powder (maximum particle size: 200 μm, purity: 99.99%) are uniformly filled in a graphite tray to a thickness of 3 cm, and then at 650 ° C for 3 hours in a nitrogen atmosphere at 0.3 atm.
r, After reacting at 750 ° C for 2 hours, further up to 1000 ° C at 30 ° C /
The temperature was raised in 1 hr, and the temperature was increased to 1 atm in a nitrogen atmosphere, and the reaction was carried out for 5 hr to obtain a reaction mass. In the same manner as in the production of α-silicon nitride powder described above, coarse particles were removed and classified to obtain powder A-16.
I got As a result of X-ray diffraction, it was aluminum nitride containing 0.13% of unreacted aluminum.

Production of β-sialon 42 parts of metal Si powder (maximum particle size 149 μm, average particle size 10 μm, purity 99.9%), fused silica powder (maximum particle size 44 μm, average particle size 5 μm, purity 99.9%) 29 parts, metal Al powder (Maximum particle size 44 μm, average particle size 10 μm, purity 99.9%) 47 parts and α-
68 parts of alumina were blended.

This was mixed in a V-type blender for 20 minutes, then a 10% aqueous solution of an ammonium salt of carboxymethylcellulose was added in an amount of 8%, kneaded with a roll mill, and molded. After heating for a period of time, a nitrided sintered body was manufactured, pulverized for 6 hours and then classified to obtain powder A-17. X-ray diffraction results: metal Si 0.06%, metal aluminum
0.11%, α-alumina 2.5%, and the remainder were β-sialon.

Manufacture of silicon oxynitride crystals Metallic Si powder (maximum particle size 74μm, average particle size 12μm, purity
60 parts of 99.9%) and 40 parts of raw silica powder (maximum particle diameter 44μm, average particle diameter 10μm, purity 99.9%) were mixed in a V-type blender for 20 minutes, and then a 10% aqueous solution of carboxymethylcellulose ammonium salt was divided 8% was added and kneaded with a roll mill. This was molded by press molding, dried and heated in a nitrogen gas atmosphere at 1450 to 1500 ° C. for 5 hours to produce a nitride. The nitride was subjected to primary crushing with a crusher and then finely crushed with a ball mill, coarse particles were removed with a 149 μm sieve, and classification and particle size were adjusted to obtain powder A-18. As a result of X-ray diffraction, metal Si0.
11%, β-silicon nitride 2.2%, α-silicon nitride 1.3%, the remainder was silicon oxynitride.

Production of epoxy resin composition Cresol novolak epoxy resin (epoxy equivalent 21
5) A resin composition comprising 150 parts, 45 parts of a brominated cresol novolak epoxy resin (epoxy equivalent: 350), and 87 parts of a phenol novolak resin (phenol equivalent: 107) is shown in Table 1.
Kneading a filler indicated by 2, kneading 5.6 parts of antimony trioxide, 3 parts of carbon black, 4.4 parts of carnauba wax, 2.5 parts of 2-undecylimidazole as a curing accelerator, and 5 parts of γ-glycidoxypropyltrimethoxysilane. Thereafter, the resultant was pulverized to prepare an epoxy resin composition.
These resin compositions were subjected to the following evaluation tests. Table 3 shows the results.

The measurement values described in Tables 2 to 3 were based on the following methods.

(1) Particle size Particle size measurement by laser diffraction method (Cirrus Gran
ulometer model 715).

(2) Moldability (spiral flow) The moldability was measured at a molding temperature of 170 ° C. and a molding pressure of 70 kg / cm ² using a mold conforming to the EMMI standard.

(3) Burr Using a mold having slits of predetermined thicknesses of 2, 5, 10, and 30 μm, the flow length was measured at a molding temperature of 170 ° C. and a molding pressure of 70 kg / cm ² , and the maximum value was shown.

(4) Heat dissipation Thermal conductivity measurement device (Agne “ARC-TC-1”)
Was measured at room temperature by a temperature gradient method.

(5) Heat shock resistance evaluation (T / S resistance) A 16-pin lead frame with an island size of 4 x 7.5 mm was transfer-molded with each composition, and its 16-pin DI
The P-shaped molded body was repeatedly immersed in a liquid at −196 ° C. and a liquid at 260 ° C. for 30 seconds for 200 times, and the crack occurrence rate on the surface of the molded body was determined from 50 samples.

[Effects of the Invention] By using the filler of the present invention, it is possible to obtain a resin composition having excellent spiral flow characteristics, burr characteristics and heat dissipation.

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Claims (1)

(57) [Claims] 1. A resin filler comprising an inorganic powder containing a nitride powder and / or an oxynitride powder having the following particle size characteristics. (Particle size distribution) -1μ 5-10% -2μ 6-12% -3μ 10-16% -8μ 35-47% -24μ 51-63% -48μ 67-75% -96μ 88-92% ) 9 ~ 22μm (RRS-n value) ≤0.80